A ground fault circuit interrupter (GFCI) is a leakage protection product widely used in North American and South American countries/regions such as United States and Canada. It plays an important role in protecting safety of lives and property of the people in the aforementioned areas.
For example, Chinese Patent Application No. 201210024531.5 (filed on Feb. 4, 2012), U.S. Pat. No. 8,779,875 (issued Jul. 15, 2014), and U.S. Pat. No. 8,847,712 (issued Sep. 30, 2014) disclose a socket-type ground fault circuit interrupter. The contents of these prior art documents are incorporated by reference. As shown in FIGS. 1-3, which are based on those prior art references, a ground fault circuit interrupter may include a shell (not shown in the drawings), a reset key 4, a reset mechanism disposed in the shell, a conductive assembly connecting a power supply input side to a load side; a leakage signal detection circuit, and an electromagnetic tripping mechanism whose action is controlled by the leakage signal detection circuit. The reset mechanism includes a reset support and a support return mechanism. The reset support includes a reset bracket 12 and a support reset spring 13 disposed in the reset bracket 12. The support return mechanism includes a reset pole 14, a reset key spring 17, a compression spring 24, a reset block 21, a compression spring container 220 in the reset block 21, and a reset slider 22. The reset slider 22 is disposed adjacent to and is configured to engage with the reset bracket 12.
As controlled by the reset key 4, the support return mechanism, and the electromagnetic tripping mechanism, the reset support has a first position in a reset (closed) state and a second position in a tripping (open) state. In the first position, support reset spring 13 is compressed and electrical contacts of reset bracket 12 are pressed against corresponding electrical contacts of other GFCI components (as explained in the referenced art), which permits electrical connection of the conductive assembly from a power supply input side to a load side. In the second position, support reset spring 13 is able to push reset bracket 12 such that electrical contacts of reset bracket 12 are separated from corresponding electrical contacts of the other GFCI components, thereby preventing electrical connection of the conductive assembly. The support return mechanism works in coordination with the reset support, such that the reset support is biased to slide from the first position to the second position due to the force of support reset spring 13.
As discussed in the referenced art, the reset support and support return mechanisms work as follows: From a tripped stated, when the reset key 4 is pressed, the reset pole 14 moves downward (i.e., away from the reset key 4). Provided that adequate downward pressure is provided to the reset key 4, the reset pole 14 moves downward, compressing compression spring 24, and bringing a reset locking hook 403 at the lower end of the reset pole 14 into alignment with a linkage hole 143 on the reset slider 22. Upon such alignment, an iron core 151 of the electromagnetic tripping mechanism may engage with both the reset locking hook 403 and the linkage hole 143 via an iron core reset spring 153 (not show). Engagement of the iron core 151 serves to lock the reset pole 14 and the reset slider 22 together, along with reset block 21.
Additionally, when reset key 4 is sufficiently pressed, the downward-most end of reset pole 14 is passed through a hole of a first PCB board 61, thereby separating a leaf switch 18 from a contact on the first PCB board 61 and disconnecting the leaf switch 18. As this leaf switch 18 may control an on-off state of electrical connection of the conductive assembly from a power supply input side to a load side, the provision of power supply is prevented while the reset key 4 is fully depressed. Once the reset key 4 is no longer pressed downward, key reset spring 17 returns reset key 4 to its original position, consequently pulling the downward-most end of reset pole 14 back through the hole of the first PCB board 61 and permitting the leaf switch 18 to reconnect.
As discussed in the referenced art, when the reset sliding block 22 is locked to reset pole 14 (and reset block 21) via an iron core 151 of an electromagnetic tripping mechanism and after reset key 4 is no longer being pressed, the support return mechanism moves upward due to the force of reset key spring 17 and reset sliding block 22 presses against reset bracket 12, maintaining the reset support in the first position.
When the electromagnetic tripping mechanism is tripped, the iron core 151 of the electromagnetic tripping mechanism is withdrawn, thereby unlocking reset pole 14 and reset slider 22 (and reset block 21) from one another. This unlocking allows bracket reset spring 13 to push reset bracket 12 further in the direction of the support return mechanism, which disconnects the electrical contacts of reset bracket 12 and returns the reset support to the second (open) position. Under the force of the compression spring 24 and bracket reset spring 13 (transferred via corresponding inclined surfaces of reset bracket 12 and reset sliding block 22), the reset slider 22 and the reset block 21 both separate from one another and move away from the reset key 4 along the reset pole 14.
The above-described existing ground fault circuit interrupter has the following structural disadvantages. First, a leaf switch having a complex structure is required in order to permit a reset mechanism is to drive the leaf switch to control the on-off state of the conductive assembly. This increases the quantity of complex parts in the ground fault circuit interrupter, which increases the manufacturing cost of the ground fault circuit interrupters.
Second, the above-described ground fault circuit interrupter requires that the leaf switch 18 be disposed on a side of the PCB board opposite from the bulk of the components of the ground fault circuit interrupter. This causes the ground fault circuit interrupter to inefficiently utilize space and prevents the ground fault interrupter from being compact in structure.